"Medicine is a social science, and politics is nothing else but medicine on a large scale"—Rudolf Virchow

July 22, 2009

Canada: A flu skeptic weighs in

I'm always interested when a skeptic turns up, especially if the skeptic has some credentials. Here's Dr. Robert Schabas, who was Ontario's Chief Medical Officer of Health from 1987-1997, in The Star: H1N1's oink is proving to be far worse than its bite. Excerpt:

Toronto is gripped in a frenzy of worry about the dreaded "second wave" of H1N1 now scheduled for this fall.

A severe "second wave" of H1N1 is possible, in the same sense that it's possible the Blue Jays will win the World Series this year.

Science and public policy need to look beyond possibilities and also consider probabilities. Our appreciation of probabilities should be based on evidence, not speculation.
The evidence strongly suggests that a severe "second wave" of H1N1 is very unlikely. It will almost certainly be merely the latest instalment in a growing list of pandemic false alarms.

Let's begin by putting this warning in some context. This is the fourth pandemic alarm in the past six years. The first three have been wrong.

The first alarm was about SARS. At the time, pundits predicted that SARS would become a pandemic and that more than 100 million people would die. Wrong. SARS died out because it was not really very infectious outside of hospitals.

The second alarm was for H5N1 "bird flu." We were told that this disease would leap across the species barrier and cause a devastating human pandemic. More than a billion people were supposed to die in an imminent catastrophe of unprecedented dimensions.

Wrong. H5N1 remains a disease of birds that rarely infects people who live in close contact with birds. There is no scientific reason to expect this to change.

The third alarm was for the dreaded "first wave" of H1N1. All of our pandemic planning had been directed toward this "first wave." It was supposed to hit fast and hard. Eight to 12 million Canadians were supposed to fall ill over two to three months. Between 10,000 and 50,000 Canadians were supposed to die.

H1N1 may have hit quickly but in public health terms it has not hit hard. Regular seasonal influenza kills 2,000 to 4,000 Canadians every year. H1N1 has killed fewer than 50 people in Canada in its "first wave."

So now we are warned about the H1N1 "second wave." How serious is the risk? There are three general arguments supporting the "second wave" hypothesis. None of them stand up well to scrutiny.

The first argument is historical, based on the 1918 "Spanish Flu" pandemic. In the spring of 1918 there was a relatively mild "first wave" of influenza followed by a much more severe "second wave" in the fall.

The problem is that the cause of influenza was a mystery in 1918. The influenza virus itself was not discovered until 1933. There is no reliable basis to conclude that the two 1918 "waves" were caused by the same virus.

Based on everything we have learned about influenza in the last 75 years, it is much more likely that the mild 1918 "first wave" was caused by a different influenza virus. This argument is more folklore than science.

The second argument warns that H1N1 could "mutate" and become more virulent. Mutations are extremely common in all viruses, indeed in all living organisms. Important sustainable behavioural changes caused by mutations are, however, very, very rare.

Mutations are just the raw material of evolution. Natural selection favours micro-organisms that don't kill their hosts. Evolutionary trends in infectious diseases are consistently in the direction of lower virulence. Our experience with influenza and every other infectious disease supports this. The mutation argument is science-fiction.

The third argument is that H1N1 will be more severe when it hits during our normal flu season – the cold, dry months of winter. This hypothesis is, at least, coherent. It is also testable. Our eyes should be glued on the southern hemisphere where H1N1 is now active during their normal flu season.

And the news is good. Australia is now two months into its H1N1 "first wave" and it hasn't been substantially more severe than what we faced. Furthermore, the data now suggest the Australian outbreak is ending. The seasonal hypothesis may be reasonable but the evidence is against it.

Read the whole piece, and I'd welcome your comments. I'll just add some quick responses to the excerpt.

First, I'm glad to see some skepticism about a second wave in the fall. Most arguments about it have been from analogy with 1918-19. But this is a different virus and may behave differently.

But I'm startled by Dr. Schabas's assertion that spring 1918 and fall 1918 were two different viruses. I haven't read everything about the Spanish flu, but this is the first time I've seen such an argument. I would love to see Dr. Schabas's sources on this.

I was paying some attention to SARS at the time (that's what got me interested in blogging, because the SARS bloggers were doing so much better than the mainstream media). But I honestly don't recall anyone, pundits or otherwise, who said it could kill 100 million people.

And forgive me, but the good doctor is out for a long, long lunch when he says: The third alarm was for the dreaded "first wave" of H1N1. All of our pandemic planning had been directed toward this "first wave."

All of our pandemic planning had been for H5N1, and then H1N1 came out of nowhere and hit us over the head. H1N1 was simply not in the picture, least of all as a disease originating in North America and spreading elsewhere. The standard paranoid scenario had been squalid Asian village -> infected visiting westerner -> trip home -> pandemic.

So everyone had to fall back, reorganize, and see how much of their battle plan had survived this first contact with an outflanking enemy we hadn't even known was in the field.

The short answer: Not much. But it was still an influenza virus, and pandemics come in waves, so we could assume this one would also come in waves.

Dr. Schabas finds the news "good" in the southern hemisphere's winter. He reminds me of La Rochefoucauld's famous observation that "We always find the strength to endure the misfortunes of others."

The Australians, New Zealanders, Chileans, and Argentines (to name a few) are taking H1N1 more personally. They're not so stoic about losing their pregnant young women and their children with the now-proverbial "underlying health conditions."

Dr. Schabas argues that mutations in viruses are always in the direction of lower virulence, and anything else is "science fiction." As a lifelong author of science fiction, I advise him to stick to medicine. Yersinia pestis in the 14th century, and Lehman Brothers in the 21st, both went for the big payoffs, and those gambles paid off very well in the short term. In the long term, as Keynes reminds us, we are all dead anyway.

I've been following H5N1 and now H1N1 since spring 2004 on one basic premise: As a lifelong teacher of business English and writer of mass-market fiction, I know little to nothing about influenza. This blog, with almost 12,000 posts, is proof of my ignorance. But it's also my way of educating myself about influenza, and I've learned enough to understand that I'm not the only ignoramus.

Dr. Schabas may well be right, and I hope he is. But his arguments need sourcing and defense. I hope he or others will provide them.

Comments

Canada: A flu skeptic weighs in

I'm always interested when a skeptic turns up, especially if the skeptic has some credentials. Here's Dr. Robert Schabas, who was Ontario's Chief Medical Officer of Health from 1987-1997, in The Star: H1N1's oink is proving to be far worse than its bite. Excerpt:

Toronto is gripped in a frenzy of worry about the dreaded "second wave" of H1N1 now scheduled for this fall.

A severe "second wave" of H1N1 is possible, in the same sense that it's possible the Blue Jays will win the World Series this year.

Science and public policy need to look beyond possibilities and also consider probabilities. Our appreciation of probabilities should be based on evidence, not speculation.
The evidence strongly suggests that a severe "second wave" of H1N1 is very unlikely. It will almost certainly be merely the latest instalment in a growing list of pandemic false alarms.

Let's begin by putting this warning in some context. This is the fourth pandemic alarm in the past six years. The first three have been wrong.

The first alarm was about SARS. At the time, pundits predicted that SARS would become a pandemic and that more than 100 million people would die. Wrong. SARS died out because it was not really very infectious outside of hospitals.

The second alarm was for H5N1 "bird flu." We were told that this disease would leap across the species barrier and cause a devastating human pandemic. More than a billion people were supposed to die in an imminent catastrophe of unprecedented dimensions.

Wrong. H5N1 remains a disease of birds that rarely infects people who live in close contact with birds. There is no scientific reason to expect this to change.

The third alarm was for the dreaded "first wave" of H1N1. All of our pandemic planning had been directed toward this "first wave." It was supposed to hit fast and hard. Eight to 12 million Canadians were supposed to fall ill over two to three months. Between 10,000 and 50,000 Canadians were supposed to die.

H1N1 may have hit quickly but in public health terms it has not hit hard. Regular seasonal influenza kills 2,000 to 4,000 Canadians every year. H1N1 has killed fewer than 50 people in Canada in its "first wave."

So now we are warned about the H1N1 "second wave." How serious is the risk? There are three general arguments supporting the "second wave" hypothesis. None of them stand up well to scrutiny.

The first argument is historical, based on the 1918 "Spanish Flu" pandemic. In the spring of 1918 there was a relatively mild "first wave" of influenza followed by a much more severe "second wave" in the fall.

The problem is that the cause of influenza was a mystery in 1918. The influenza virus itself was not discovered until 1933. There is no reliable basis to conclude that the two 1918 "waves" were caused by the same virus.

Based on everything we have learned about influenza in the last 75 years, it is much more likely that the mild 1918 "first wave" was caused by a different influenza virus. This argument is more folklore than science.

The second argument warns that H1N1 could "mutate" and become more virulent. Mutations are extremely common in all viruses, indeed in all living organisms. Important sustainable behavioural changes caused by mutations are, however, very, very rare.

Mutations are just the raw material of evolution. Natural selection favours micro-organisms that don't kill their hosts. Evolutionary trends in infectious diseases are consistently in the direction of lower virulence. Our experience with influenza and every other infectious disease supports this. The mutation argument is science-fiction.

The third argument is that H1N1 will be more severe when it hits during our normal flu season – the cold, dry months of winter. This hypothesis is, at least, coherent. It is also testable. Our eyes should be glued on the southern hemisphere where H1N1 is now active during their normal flu season.

And the news is good. Australia is now two months into its H1N1 "first wave" and it hasn't been substantially more severe than what we faced. Furthermore, the data now suggest the Australian outbreak is ending. The seasonal hypothesis may be reasonable but the evidence is against it.

Read the whole piece, and I'd welcome your comments. I'll just add some quick responses to the excerpt.

First, I'm glad to see some skepticism about a second wave in the fall. Most arguments about it have been from analogy with 1918-19. But this is a different virus and may behave differently.

But I'm startled by Dr. Schabas's assertion that spring 1918 and fall 1918 were two different viruses. I haven't read everything about the Spanish flu, but this is the first time I've seen such an argument. I would love to see Dr. Schabas's sources on this.

I was paying some attention to SARS at the time (that's what got me interested in blogging, because the SARS bloggers were doing so much better than the mainstream media). But I honestly don't recall anyone, pundits or otherwise, who said it could kill 100 million people.

And forgive me, but the good doctor is out for a long, long lunch when he says: The third alarm was for the dreaded "first wave" of H1N1. All of our pandemic planning had been directed toward this "first wave."

All of our pandemic planning had been for H5N1, and then H1N1 came out of nowhere and hit us over the head. H1N1 was simply not in the picture, least of all as a disease originating in North America and spreading elsewhere. The standard paranoid scenario had been squalid Asian village -> infected visiting westerner -> trip home -> pandemic.

So everyone had to fall back, reorganize, and see how much of their battle plan had survived this first contact with an outflanking enemy we hadn't even known was in the field.

The short answer: Not much. But it was still an influenza virus, and pandemics come in waves, so we could assume this one would also come in waves.

Dr. Schabas finds the news "good" in the southern hemisphere's winter. He reminds me of La Rochefoucauld's famous observation that "We always find the strength to endure the misfortunes of others."

The Australians, New Zealanders, Chileans, and Argentines (to name a few) are taking H1N1 more personally. They're not so stoic about losing their pregnant young women and their children with the now-proverbial "underlying health conditions."

Dr. Schabas argues that mutations in viruses are always in the direction of lower virulence, and anything else is "science fiction." As a lifelong author of science fiction, I advise him to stick to medicine. Yersinia pestis in the 14th century, and Lehman Brothers in the 21st, both went for the big payoffs, and those gambles paid off very well in the short term. In the long term, as Keynes reminds us, we are all dead anyway.

I've been following H5N1 and now H1N1 since spring 2004 on one basic premise: As a lifelong teacher of business English and writer of mass-market fiction, I know little to nothing about influenza. This blog, with almost 12,000 posts, is proof of my ignorance. But it's also my way of educating myself about influenza, and I've learned enough to understand that I'm not the only ignoramus.

Dr. Schabas may well be right, and I hope he is. But his arguments need sourcing and defense. I hope he or others will provide them.